The invention relates to a system for teleprinter traffic, in which an information sending station, comprising a transmitter-receiver, transmits information to an information receiving station, comprising a transmitter-receiver, and in which the information receiving station can transmit signals to the information sending station for the repeated transmission of signal parts received multilated by the information receiving station.
Systems of this sort are generally known and are usually defined as systems according to the ARQ-system (Automatic Error Correcting System). The working of these systems is particularly described in Recommendation 476 of the "Comite Consultatif International des Radio-communications" (CCIR).
A drawback of the known system is that its efficiency is low because of the frequent switching for transmitting and receiving and the long waits occurring when executing the repetition procedure. This drawback is felt all the more in the case of a long propagation time caused by a great distance between the information sending station and the information receiving station.
Though the known system was originally used in VHF (very high frequency) circuits mainly, it is now more and more used in the VHF-UHF (ultra high frequency) frequency band. The wide-band frequency channels used in this band allow a quick signal transmission, so that propagation delays begin to play a much more important part.